<?php
/**
 * Settings helper for AI Content by Parallax options.
 *
 * @package AIContentByParallax
 */

namespace AIContentByParallax\Core;

defined( 'ABSPATH' ) || exit;

/**
 * Manage plugin settings stored in options.
 */
class Settings {
	const OPTION_KEY                           = 'ai_content_by_parallax_settings';
	const CLIENT_API_KEY_KEY                   = 'client_api_key';
	const CLIENT_NAME_KEY                      = 'client_name';
	const CLIENT_DESCRIPTION_KEY               = 'client_description';
	const ENABLE_CATEGORY_LONG_DESCRIPTION_KEY = 'enable_category_long_description';
	const ENABLE_YOAST_TERM_SYNC_KEY           = 'enable_yoast_term_sync';
	const DISABLE_YOAST_TERM_SYNC_KEY          = 'disable_sync_term_seo_to_yoast';
	const INCLUDE_DRAFTS_KEY                   = 'include_drafts';
	const EXCLUDED_PRODUCT_IDS_KEY             = 'excluded_product_ids_csv';
	const EXCLUDED_CATEGORY_IDS_KEY            = 'excluded_category_ids_csv';
	const MAX_BATCH_ITEM_IDS_KEY               = 'max_batch_item_ids';
	const API_KEY_OVERRIDE_CONSTANT            = 'EPARALLAX_API_KEY';

	// ── Declared ahead of v2.0.0 Catalog Data Sync (PLX-288) ────────────────
	// These constants declare the option-key names that v2.0.0 will use inside
	// the single serialized `ai_content_by_parallax_settings` option. Declaring
	// them here (rather than in the v2.0.0 branch) means the string values are
	// pinned in one place and v2.0.0 does not need a settings migration.
	// They are never read or written by 1.x code.

	/** Reserved: catalog data sync master toggle (bool, default false). */
	const DATA_SYNC_ENABLED_KEY = 'data_sync_enabled';

	/** Reserved: feature-flag gate for catalog sync UI (bool, default false). */
	const DATA_SYNC_FEATURE_FLAG_KEY = 'data_sync_feature_flag';

	/** Reserved: opaque cursor for product catalog pagination (string|null). */
	const CATALOG_SYNC_CURSOR_PRODUCTS_KEY = 'catalog_sync_cursor_products';

	/** Reserved: opaque cursor for category catalog pagination (string|null). */
	const CATALOG_SYNC_CURSOR_CATEGORIES_KEY = 'catalog_sync_cursor_categories';

	/** Reserved: number of items per catalog sync page (int, default 100). */
	const CATALOG_CHUNK_SIZE_KEY = 'catalog_chunk_size';

	/** Reserved: UTC datetime string when the user consented to catalog sync (string|null). */
	const DATA_SYNC_CONSENT_AT_KEY = 'data_sync_consent_at';

	/**
	 * Default max item IDs accepted per batch request.
	 */
	private const DEFAULT_MAX_BATCH_ITEM_IDS = 1000;

	/**
	 * Minimum allowed max item IDs.
	 */
	private const MIN_MAX_BATCH_ITEM_IDS = 1;

	/**
	 * Maximum allowed max item IDs to prevent oversized requests.
	 */
	private const MAX_MAX_BATCH_ITEM_IDS = 5000;

	/**
	 * Retrieve a single option value.
	 *
	 * @param string $key Option key.
	 * @param mixed  $default_value Default value if missing.
	 * @return mixed
	 */
	public static function get( string $key, $default_value = null ) {
		$options = get_option( self::OPTION_KEY, array() );
		return $options[ $key ] ?? $default_value;
	}

	/**
	 * Get the effective Parallax API key (define override takes precedence).
	 *
	 * @return string
	 */
	public static function get_client_api_key(): string {
		$override = Env::get_string_constant( self::API_KEY_OVERRIDE_CONSTANT );
		if ( null !== $override ) {
			return $override;
		}

		return trim( (string) self::get( self::CLIENT_API_KEY_KEY, '' ) );
	}

	/**
	 * Check whether the Parallax API key is overridden via define.
	 *
	 * @return bool
	 */
	public static function has_client_api_key_override(): bool {
		return null !== self::get_client_api_key_override();
	}

	/**
	 * Get the configured API key override value.
	 *
	 * @return string|null
	 */
	public static function get_client_api_key_override(): ?string {
		return Env::get_string_constant( self::API_KEY_OVERRIDE_CONSTANT );
	}

	/**
	 * Migrate legacy Yoast term sync option to the disable flag (one-time).
	 */
	public static function maybe_migrate_yoast_term_sync(): void {
		$options = get_option( self::OPTION_KEY, array() );
		if ( ! is_array( $options ) ) {
			return;
		}

		if ( array_key_exists( self::DISABLE_YOAST_TERM_SYNC_KEY, $options ) ) {
			return;
		}

		if ( ! array_key_exists( self::ENABLE_YOAST_TERM_SYNC_KEY, $options ) ) {
			return;
		}

		$legacy_enabled                               = (bool) $options[ self::ENABLE_YOAST_TERM_SYNC_KEY ];
		$options[ self::DISABLE_YOAST_TERM_SYNC_KEY ] = ! $legacy_enabled;
		unset( $options[ self::ENABLE_YOAST_TERM_SYNC_KEY ] );
		update_option( self::OPTION_KEY, $options );
	}

	/**
	 * Get all plugin settings.
	 *
	 * @return array
	 */
	public static function get_all(): array {
		return get_option( self::OPTION_KEY, array() );
	}

	/**
	 * Update plugin settings with new values.
	 *
	 * @param array $new_options New options to merge.
	 */
	public static function update( array $new_options ): void {
		$options         = get_option( self::OPTION_KEY, array() );
		$updated_options = array_merge( $options, $new_options );
		update_option( self::OPTION_KEY, $updated_options );
	}

	/**
	 * Get the configured client name or blog name fallback.
	 *
	 * @return string
	 */
	public static function get_client_name(): string {
		return self::get( self::CLIENT_NAME_KEY, get_bloginfo( 'name' ) );
	}

	/**
	 * Get the configured client description or blog description fallback.
	 *
	 * @return string
	 */
	public static function get_client_desc(): string {
		return self::get( self::CLIENT_DESCRIPTION_KEY, get_bloginfo( 'description' ) );
	}

	/**
	 * Get excluded product IDs as an integer array.
	 *
	 * @return int[]
	 */
	public static function get_excluded_product_ids(): array {
		return self::parse_csv_ids( self::get( self::EXCLUDED_PRODUCT_IDS_KEY, '' ) );
	}

	/**
	 * Get excluded category IDs as an integer array.
	 *
	 * @return int[]
	 */
	public static function get_excluded_category_ids(): array {
		return self::parse_csv_ids( self::get( self::EXCLUDED_CATEGORY_IDS_KEY, '' ) );
	}

	/**
	 * Determine whether draft products should be included for optimize flows.
	 *
	 * @return bool
	 */
	public static function include_drafts(): bool {
		$value = self::get( self::INCLUDE_DRAFTS_KEY, '0' );
		if ( is_bool( $value ) ) {
			return $value;
		}
		return '1' === (string) $value;
	}

	/**
	 * Get the product statuses used for optimize flows.
	 *
	 * @return string[]
	 */
	public static function get_product_statuses_for_optimize(): array {
		return self::include_drafts()
			? array( 'publish', 'draft' )
			: array( 'publish' );
	}

	/**
	 * Get the maximum allowed item IDs per batch request.
	 *
	 * @return int
	 */
	public static function get_max_batch_item_ids(): int {
		$value = absint( self::get( self::MAX_BATCH_ITEM_IDS_KEY, self::DEFAULT_MAX_BATCH_ITEM_IDS ) );
		if ( ! $value ) {
			$value = self::DEFAULT_MAX_BATCH_ITEM_IDS;
		}

		return self::clamp_max_batch_item_ids( $value );
	}

	/**
	 * Clamp max batch item IDs to a safe range.
	 *
	 * @param int $value Raw value.
	 * @return int
	 */
	public static function clamp_max_batch_item_ids( int $value ): int {
		return max(
			self::MIN_MAX_BATCH_ITEM_IDS,
			min( self::MAX_MAX_BATCH_ITEM_IDS, $value )
		);
	}

	/**
	 * Parse a CSV/whitespace separated list of IDs into a unique int array.
	 *
	 * @param mixed $raw Raw stored value.
	 * @return int[]
	 */
	private static function parse_csv_ids( $raw ): array {
		if ( is_array( $raw ) ) {
			$raw = implode( ',', array_map( 'strval', $raw ) );
		}

		$value  = is_string( $raw ) ? $raw : '';
		$tokens = preg_split( '/[\s,]+/', $value, -1, PREG_SPLIT_NO_EMPTY );
		$ids    = array();

		if ( is_array( $tokens ) ) {
			foreach ( $tokens as $token ) {
				if ( ! preg_match( '/^\d+$/', $token ) ) {
					continue;
				}
				$id = absint( $token );
				if ( $id > 0 ) {
					$ids[] = $id;
				}
			}
		}

		return array_values( array_unique( $ids ) );
	}
}